US Patent 7114938 Lithographic apparatus for molding ultrafine features

An apparatus for performing imprint lithography especially useful in creating patterns with ultrafine features on a substrate. The apparatus comprises a substrate having moldable surface carried on a first block, a mold having a molding surface carried on a second block, positioners for moving the first and second blocks relative to each other, a sensor of the relative positions of the blocks and a controller for controlling the relative positions of the blocks.